There have been proposed various problem diagnosis systems which include a communication device in a vehicle to enable sending and receiving of information to/from external devices, inform a user of the occurrence of a problem when the problem occurs and send information concerning the problem to an external device, and allow grasping of the problem of the vehicle from outside by using a terminal device located in a dealership, a service station etc.
A vehicle includes a number of vehicle-mounted devices using ECUs (Electronic Control Units) for performing various control operations for a power train system, a safety control system, a body system etc. When a problem occurs, information including data retained in the ECUs or data outputted from the ECUs is useful to investigate the cause of the problem.
Patent Document 1 discloses a vehicle management system which self-diagnoses a fuel system, wirelessly sends real-time diagnosis information indicating the result of the self-diagnosis to an external device, and accumulates the diagnosis information in a database in the external device in order to enable analyzing the condition of the fuel system in the future.
Patent document 2 discloses a remote maintenance apparatus which sends vehicle driving information and positional information obtained from specific sensors to a call center to allow the call center to determine the symptoms of a problem and the necessity of taking emergency measures based on the vehicle driving information and make an appointment with a service station automatically, and is thereby capable of eliminating the time-consuming work for the user.
Patent Document 3 discloses a vehicle condition monitor system which, when problem information is detected in a section subjected to a problem diagnosis, obtains problem history information corresponding to the problem information from an external device, thereby making it possible to accurately grasping the problem and a problem occurrence tendency by analysis of the problem history information.
Patent Document 4 discloses a remote control system which realizes wireless remote control by wirelessly sending vehicle information including the result of control performed by a vehicle-mounted device in response to a request for remote control to an external device.
Patent Document 5 discloses a diagnosis system which sends information about the connection status of a vehicle-mounted network to an external device, thereby allowing the external device to diagnose the propriety of the connection status of the vehicle-mounted network.
Patent Document 6 discloses a vehicle maintenance system including a terminal device used by a user, a terminal device mounted in a vehicle, a dealer terminal device used by a dealer, and a server apparatus for controlling sending and receiving of data between the respective terminal devices, thereby enabling sending and receiving of maintenance information between the respective devices.    Patent Document 1: Japanese Patent Application Laid-Open No. 2002-322940    Patent Document 2: Japanese Patent Application Laid-Open No. 2002-109690    Patent Document 3: Japanese Patent Application Laid-Open No. 2005-146905    Patent Document 4: Japanese Patent Application Laid-Open No. 2006-192967    Patent Document 5: Japanese Patent Application Laid-Open No. 2007-99145    Patent Document 6: Japanese Patent Application Laid-Open No. 2007-213114